documentary (adj.)youdaoicibaDictYouDict[documentary 词源字典]
c. 1810, "pertaining to documents," from document + -ary. Meaning "factual, meant to provide a record of something" is from 1926, from French film documentarie (1924). The noun (short for documentary film) is attested from 1935. Docudrama is a 1961 coinage.[documentary etymology, documentary origin, 英语词源]